using UnityEngine.UI;
using UnityEngine;

/// <summary>
/// 用来射线检测（不会产生额外Draw Call）
/// </summary>
[RequireComponent(typeof(CanvasRenderer))]
public class EmptyRaycast : Graphic
{
    public override void SetMaterialDirty()
    {
        return;
    }

    public override void SetVerticesDirty()
    {
        return;
    }

    /// Probably not necessary since the chain of calls `Rebuild()`->`UpdateGeometry()`->`DoMeshGeneration()`->`OnPopulateMesh()` won't happen; so here really just as a fail-safe.
    protected override void OnPopulateMesh(VertexHelper vh)
    {
        vh.Clear();
        return;
    }
}